An initial flight stability of unguided rockets or guided missiles greatly depends on a misalignment angle of a thrust line of a propulsion device. The misalignment angle of the thrust line of a propulsion system denotes a deviation angle that the thrust line is deviated from a centerline of the propulsion system upon burning of the propulsion system.
The causes of the thrust line misalignment of the propulsion system may include, for example, nozzle offset, nozzle misalignment, propellant charge misalignment and the like. Particularly, for the unguided rocket, upon the generation of the thrust line misalignment, accuracy rate as well as flight stability are drastically lowered.
For the prevention of the thrust line misalignment, a method of coupling a nozzle by use of screws or bolts may be employed. However, the coupling method needs the thickness of the nozzle which is as thick as allowing the coupling of the bolts, thereby causing an increase in a weight of a rocket propulsion device. Furthermore, the coupling method requires additional assembly processes, such as a hole processing for the bolt coupling, a bolt assembly and the like.
To solve such problems, a rocket propulsion device which is capable of preventing the misalignment of the thrust line of the propulsion device can be considered.